Respuesta :
Answer:
The cost of one pack of paper was $0.90 and the cost of one box of pens was $2.00
Step-by-step explanation:
Let
x----> the cost of one pack of paper
y---> the cost of one box of pens
we know that
10x+12y=33 ----> equation A
15x+7y=27.50 ---> equation B
Solve the system of equations by graphing
Remember that the solution of the system of equations is the intersection point both graphs
The solution is the point (0.9,2)
see the attached figure
Therefore
The cost of one pack of paper was $0.90
The cost of one box of pens was $2.00
Answer:
pens = $2
paper = .9
Step-by-step explanation:
p = price of a pack of paper
n = price of a box of pens
10p + 12n = 33
15p + 7n = 27.50
Multiply the first equation by 3
3(10p + 12n )= 33*3
30p +36n = 99
Multiply the second equation by -2
-2(15p + 7n) = 27.50*-2
-30p -14n = -55
Add the 2 modified equations together
30p +36n = 99
-30p -14n = -55
--------------------
22n = 44
Divide each side by 22
22n/22 = 44/22
n =2
Each box of pens is $2
Now we can find the price of the paper
10p + 12n = 33
10p +12(2) = 33
10p +24 =33
Subtract 24 from each side
10p+24-24=33-24
10p = 9
Divide by 10
10p/10 =9/10
p = .9